Will 330/360cc make me a D cup from a 32A? I'm 5'5", around 126 lbs. I'm worried about regretting not going big enough.

Thank you for your question. While it is rather difficult to give concise and accurate advice online especially without pictures, in general if you are small A cup and wish to be a D cup, I would recommend using larger implants than the ones you have already mentioned. You would likely have size regret with even 360 mL implants which may give you a C cup and not a D cup. The ideal thing to do is to have another discussion with your plastic surgeon or schedule a Skype consultation.

Of course whether or not breast implants in the 330 cc to 360 cc range will make you a D cup depends on how much breast tissue you have, what cup size you are now, and whether the D cup bra will be the same manufacturer style and shape as your current bra.It is very difficult if not impossible to accurately estimate cup size based on cc of implant.  However a general rule is that it takes 200 cc of breast implant to increase you by a cup size in the same bra.  Therefore if you're currently an a cup using the same bra you may need as much as 500-600 cc for a D cup breast.  However based on your current examination of your breast base width and your chest size it may be impossible to for you to have a breast implant that large.You need an examination by your board certified plastic surgeon which includes a breast implant sizing system evaluation as well as measurements of your breast base width and other measurements.  Your surgeon may then refer to the chart to help choose an appropriately sized implant for your body.More information on choosing breast implant size please read the following link:

Thank you for the question.  There is no accurate/reliable/predictable correlation between size/profile breast implant utilized and cup size achieved. Despite your good description of goals, online consultants will not be able to provide you with specific enough advice to be truly helpful. Ultimately, careful communication of your goals (in my practice I prefer the use of goal pictures and direct examination/communication in front of a full-length mirror)  will be critical.
Generally speaking, the best online advice I can give to ladies who are considering  breast augmentation surgery ( regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully.  Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.
2. Have a full discussion and communication regarding your desired goals  with your plastic surgeon. This communication will be critical in determining  breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as  “natural” or "D cup” etc means different things to different people and therefore prove unhelpful.
 Also, as you know, cup size varies depending on him who makes the bra; therefore, discussing desired cup  size may also be inaccurate.
3.  Once you feel you have communicated your goals clearly,  allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals.  Again, in my practice, this decision is usually made during surgery.
I hope this (and the attached link, dedicated to breast augmentation surgery concerns) helps.